Seroprevalence of anti-Leptospira antibodies in equines and associated workers-Isolation of Leptospira interrogans serogroup Canicola from equine urine.

To investigate seroprevalence of anti-Leptospira antibodies in equines and associated workers in Uruguay, 891 equine and 150 human sera were drawn; 212 equine urine samples were also taken for culture. Environmental conditions and equine raising or managing practices were recorded in all 72 visited establishments; epidemiological information was obtained from each worker. Microscopic agglutination technique (MAT) was performed with 10 Leptospira strains for equines and 18 for human sera, that were also studied with IgM indirect immunofluorescence (IgM-IIF). Equine titres ≥100 were considered positive, and human sera titres ≥200 suggested probable recent or past infection. Urines were cultured in Ellinghausen-McCullough-Johnson-Harris (EMJH) media; local identification of one obtained isolate with lipL32 PCR, Multiple Locus Variable number tandem repeat Analysis and partial rrs gene sequencing, were completed at Institut Pasteur, Paris. Estimated reactivity was 61.3% for equines, which was higher than the studied bovine national levels (21%) and mainly observed with Icterohaemorrhagiae serogroup (40.3%), Sejroe, Canicola, Pomona or Ballum. Aged animals from slaughterhouses and cattle farms were the most frequently positive. Multiple regression analysis confirmed a significant association between seropositivity and equine age. Only one positive culture could be fully studied, and confirmed to be Leptospira interrogans serogroup Canicola; it was added to the MAT antigen panel and revealed fairly frequent reaction with equine and human sera. Three workers (2%) showed titres = 200 with Icterohaemorrhagiae or Canicola serogroups, without recent clinical manifestations. Their attended equines reacted with the same serogroups, suggesting common source infections or infection transmitted by equines. Three other humans yielded titres = 100, and none of the 150 showed an IgM-IIF-positive result. Equines seem not to be an important origin of regional human leptospirosis, except perhaps during acute animal infection. More culture work is required to study intensity and lapses of leptospiruria, as well as to further identify circulating strains.

Tracing Back the Evolutionary Route of Enteroinvasive Escherichia coli (EIEC) and Shigella Through the Example of the Highly Pathogenic O96:H19 EIEC Clone.

Enteroinvasive Escherichia coli (EIEC) cause intestinal illness through the same pathogenic mechanism used by Shigella spp. The latter species can be typed through genomic and phenotypic methods used for E. coli and have been proposed for reclassification within E. coli species. Recently the first appearance of a highly pathogenic EIEC O96:H19 was described in Europe as the causative agent of two large outbreaks that occurred in Italy and in the United Kingdom. In contrast to Shigella spp and to the majority of EIEC strains, EIEC O96:H19 fermented lactose, lacked pathoadaptive mutations, and showed good fitness in extracellular environment, similarly to non-pathogenic E. coli, suggesting they have emerged following acquisition of the invasion plasmid by a non-pathogenic E. coli. Here we describe the whole genome comparison of two EIEC O96:H19 strains isolated from severe cases of diarrhea in Uruguay in 2014 with the sequences of EIEC O96:H19 available in the public domain. The phylogenetic comparison grouped all the O96:H19 strains in a single cluster, while reference EIEC strains branched into different clades with Shigella strains occupying apical positions. The comparison of the virulence plasmids showed the presence of a complete conjugation region in at least one O96:H19 EIEC. Reverse Transcriptase Real Time PCR experiments confirmed in this strain the expression of the pilin-encoding gene and conjugation experiments suggested its ability to mobilize an accessory plasmid in a recipient strain. Noteworthy, the tra region was comprised between two reversely oriented IS600 elements, which were also found as remnants in another EIEC O96:H19 plasmid lacking the tra locus. We hypothesize that an IS-mediated recombination mechanism may have caused the loss of the conjugation region commonly observed in EIEC and Shigella virulence plasmids. The results of this study support the hypothesis of EIEC originating from non-pathogenic E. coli through the acquisition of the virulence plasmid via conjugation. Remarkably, this study showed the ability of a circulating EIEC strain to mobilize plasmids through conjugation, suggesting a mechanism for the emergence of novel EIEC clones.

Presence of genes encoding enterotoxins in Staphylococcus aureus isolates recovered from food, food establishment surfaces and cases of foodborne diseases.

The aim of this study was to describe the microbiological characteristics and profile of genes encoding enterotoxins in 95 Staphylococcus aureus isolates obtained between April 2011 and December 2014 from foodstuffs, persons and surfaces of retail food stores. After microbiological identification and antimicrobial susceptibility testing, polymerase chain reactions (PCR) were performed, targeting sea, seb, sec, sed and see genes that code for classical enterotoxins (ET) A-E, and three additional genes: seg , seh and sei , coding for so-called "new enterotoxins" G, H and I. The isolates were characterized by Pulsed Field Gel Electrophoresis (PFGE), and five selected isolates were further analyzed through Multi Locus Sequence Typing (MLST). It is noteworthy that 54.7% of the examined isolates harbored one or more of the investigated ET gene types. Most positive isolates carried more than one ET gene up to five types; seg was the most frequent ET gene, followed by sei. Five enterotoxin-coding isolates also coded for some antimicrobial resistance genes. Two of them, and four additional non-enterotoxic isolates carried erm genes expressing inducible clindamycin resistance. PFGE-types were numerous and diverse, even among enterotoxin-coding strains, because most isolates did not belong to known foodborne outbreaks and the sampling period was long. MLST profiles were also varied, and a new ST 3840 was described within this species. ST 88 and ST 72 enterotoxin-coding isolates have been identified in other regions in association with foodborne outbreaks. This manuscript reports the first systematic investigation of enterotoxin genes in S. aureus isolates obtained from foodstuffs and infected people in Uruguay.

Seroprevalence of leptospirosis in human groups at risk due to environmental, labor or social conditions.

Leptospirosis is important in Uruguay due to the economic loss caused by the diseases of production animals, mainly bovines, and also due to frequent human infection. We decided to study anti-Leptospira antibodies in the sera of dairy workers, rice laborers, veterinarians, suburban slum dwellers and garbage recyclers. Our aims were to estimate the seroprevalence of infection by Leptospira spp. in these people at risk, the relative importance of the known risk factors associated with infection, and the impact of human infections in each setting. Groups at risk were identified and 35 visits to their locations were made, conducting field surveys and exchange talks for information and education. Simple epidemiological questionnaires were administered and sera samples were taken from 308 persons. The microagglutination Technique (MAT) and the IgM Indirect Immunofluorescence (IIF) assay were employed to detect antibodies. Environmental water samples, canine and equine sera were also examined. More than 45% of human sera were reactive and the studied groups were confirmed to be widely exposed to infection. Female sera were frequently reactive, though most illnesses occur in men, and the most severe cases in elderly males; the emergence and evolution of the disease may strongly depend on the host condition and functions. Animal contact and unsafe water usage were the main identified risk factors to be considered in prevention. Fifty per cent of the studied horses showed a positive MAT reaction. The underdiagnosis of the illness and its long-term symptoms require further study, as well as greater health and social attention efforts.

Diarrheagenic Escherichia coli Associated with Acute Gastroenteritis in Children from Soriano, Uruguay.

INTRODUCTION: Acute diarrheal disease still deserves worldwide attention due to its high morbidity and mortality, especially in developing countries. While etiologic determination is not mandatory for management of all individual cases, it is needed for generating useful epidemiologic knowledge. Diarrheagenic Escherichia coli (DEC) are relevant enteropathogens, and their investigation requires specific procedures to which resources and training should be dedicated in reference laboratories. METHODOLOGY: Following the hypothesis that enteric pathogens affecting children in towns located in the interior of Uruguay may be different from those found in Montevideo, we conducted a diagnostic survey on acute diarrheal disease in 83 children under 5 years of age from populations in the south of the country. RESULTS: DEC pathotypes were the only bacterial pathogens found in diarrheal feces (20.48%), followed by rotavirus (14.45%) and enteric adenovirus (4.81%). Atypical EPEC (aEPEC) was the most frequent DEC pathotype identified, and unexpectedly, it was associated with bloody diarrheal cases. These patients were of concern and provided with early consultation, as were children who presented with vomiting, which occurred most frequently in rotavirus infections. aEPEC serotypes were diverse and different from those previously reported in Montevideo children within the same age group and different from serotypes identified in regional and international studies. Enteroinvasive (EIEC) O96 : H19, associated with large outbreaks in Europe, was also isolated from two patients. Antibiotic susceptibility of pathogenic bacteria identified in this study was higher than that observed in previous national studies, which had been mainly carried out in children from Montevideo. CONCLUSION: The reduced number of detected species, the marked prevalence of aEPEC, the scarce resistance traits, and the diverse range of serotypes in the virulent DEC identified in this study confirm that differences exist between enteropathogens affecting children from interior towns of Uruguay and those circulating among children in Montevideo.

Isolation of pathogenic Leptospira strains from naturally infected cattle in Uruguay reveals high serovar diversity, and uncovers a relevant risk for human leptospirosis.

Leptospirosis is a neglected zoonosis with worldwide distribution. The causative agents are spirochete bacteria of the Leptospira genus, displaying huge diversity of serovars, the identity of which is critical for effective diagnosis and vaccination purposes. Among many other mammalian species, Leptospira infects cattle, eliciting acute signs in calves, and chronic disease in adult animals often leading to abortions. In South America, and including in Uruguay, beef and dairy export are leading sources of national income. Despite the importance of bovine health, food safety, and bovine-related dissemination of leptospirosis to humans, extremely limited information is available as to the identity of Leptospira species and serovars infecting cattle in Uruguay and the South American subcontinent. Here we report a multicentric 3-year study resulting in the isolation and detailed characterization of 40 strains of Leptospira spp. obtained from infected cattle. Combined serologic and molecular typing identified these isolates as L. interrogans serogroup Pomona serovar Kennewicki (20 strains), L. interrogans serogroup Canicola serovar Canicola (1 strain), L. borgpetersenii serogroup Sejroe serovar Hardjo (10 strains) and L. noguchii (9 strains). The latter showed remarkable phenotypic and genetic variability, belonging to 6 distinct serogroups, including 3 that did not react with a large panel of reference serogrouping antisera. Approximately 20% of cattle sampled in the field were found to be shedding pathogenic Leptospira in their urine, uncovering a threat for public health that is being largely neglected. The two L. interrogans serovars that we isolated from cattle displayed identical genetic signatures to those of human isolates that had previously been obtained from leptospirosis patients. This report of local Leptospira strains shall improve diagnostic tools and the understanding of leptospirosis epidemiology in South America. These strains could also be used as new components within bacterin vaccines to protect against the pathogenic Leptospira strains that are actually circulating, a direct measure to reduce the risk of human leptospirosis.

Characterization of Leptospira isolates from humans and the environment in Uruguay.

Laboratory diagnosis of human leptospirosis usually relies on indirect methods exploring specific immune response. Isolation and identification of the involved strains are cumbersome, but can provide biological resources for pathogenic studies and relevant information for guiding prevention and control measures. The aim of the research we are hereby reporting was the characterization of Leptospira isolates obtained from humans and the environment in Uruguay. Blood cultures were performed from early samples of 302 Uruguayan patients, mainly rural workers, and from 36 water samples taken from their living or working environments. Eight human isolates and seven environmental isolates were obtained and analyzed by end point Polymerase Chain Reaction (PCR), Multilocus Variable Number of Tandem Repeat Analysis (MLVA) and other molecular methods. Human isolates corresponded to several serogroups and serovars of Leptospira interrogans and Leptospira kirschneri species, probably reflecting the infection with similar involved Leptospira species and serovars of an extended animal reservoir in rural settings of the country, mostly dedicated to meat and dairy production. Culture-positive patients were older than usually affected workers, and presented signs and symptoms of severe illness. A high organic and circulating bacterial burden may explain an easier positive result from these workers' samples. Environmental isolates were mainly identified as Leptospira biflexa strains, with a single L. meyeri isolate of uncertain significance.

Prevalence and serotype distribution of Listeria monocytogenes isolated from foods in Montevideo-Uruguay

ABSTRACT The aim of this work was to study the prevalence of Listeria monocytogenes in foods obtained in retail shops and food industries located in Montevideo-Uruguay, and to identify the serogroups of the obtained isolates. Three-thousand one-hundred and seventy-five food samples (frozen, deli meats, ready-to-eat and cheese) were analyzed. The obtained isolates were serogrouped by multiplex PCR and serotyped by conventional procedure. Genetic comparisons were performed using pulsed-field gel electrophoresis on a sub-set of isolates belonging to the same serotype successively recovered from the same establishment. L. monocytogenes was isolated from 11.2% of samples. The highest prevalence was observed in frozen foods (38%), followed by cheese (10%). 1/2b and 4b were the most frequently identified serotypes. In six of 236 analyzed establishments we successively recovered L. monocytogenes isolates belonging to the same serotype. Most of them corresponded to serotype 1/2b. Pulsed-field gel electrophoresis profiles suggest that at least 33% of L. monocytogenes 1/2b isolates are genetically related and that may remain viable for prolonged periods. The observed prevalence of L. monocytogenes was lower than reported in neighboring countries. Our findings highlight the role that frozen foods may play in the spread of this pathogen, and the relevance of serotypes 1/2b and 4b.

Prevalence and serotype distribution of Listeria monocytogenes isolated from foods in Montevideo-Uruguay.

The aim of this work was to study the prevalence of Listeria monocytogenes in foods obtained in retail shops and food industries located in Montevideo-Uruguay, and to identify the serogroups of the obtained isolates. Three-thousand one-hundred and seventy-five food samples (frozen, deli meats, ready-to-eat and cheese) were analyzed. The obtained isolates were serogrouped by multiplex PCR and serotyped by conventional procedure. Genetic comparisons were performed using pulsed-field gel electrophoresis on a sub-set of isolates belonging to the same serotype successively recovered from the same establishment. L. monocytogenes was isolated from 11.2% of samples. The highest prevalence was observed in frozen foods (38%), followed by cheese (10%). 1/2b and 4b were the most frequently identified serotypes. In six of 236 analyzed establishments we successively recovered L. monocytogenes isolates belonging to the same serotype. Most of them corresponded to serotype 1/2b. Pulsed-field gel electrophoresis profiles suggest that at least 33% of L. monocytogenes 1/2b isolates are genetically related and that may remain viable for prolonged periods. The observed prevalence of L. monocytogenes was lower than reported in neighboring countries. Our findings highlight the role that frozen foods may play in the spread of this pathogen, and the relevance of serotypes 1/2b and 4b.

Enteropathogens associated with acute diarrhea in children from households with high socioeconomic level in uruguay.

Infectious diarrhea, a common disease of children, deserves permanent monitoring in all social groups. To know the etiology and clinical manifestations of acute diarrhea in children up to 5 years of age from high socioeconomic level households, we conducted a descriptive, microbiological, and clinical study. Stools from 59 children with acute community-acquired diarrhea were examined, and their parents were interviewed concerning symptoms and signs. Rotavirus, adenovirus, and norovirus were detected by commercially available qualitative immunochromatographic lateral flow rapid tests. Salmonella, Campylobacter, Yersinia, and Shigella were investigated by standard bacteriological methods and diarrheagenic E. coli by PCR assays. We identified a potential enteric pathogen in 30 children. The most frequent causes of diarrhea were enteropathogenic E. coli (EPEC), viruses, Campylobacter, Salmonella, and Shiga-toxin-producing E. coli (STEC). Only 2 patients showed mixed infections. Our data suggest that children with viral or Campylobacter diarrhea were taken to the hospital earlier than those infected with EPEC. One child infected with STEC O26 developed "complete" HUS. The microbiological results highlight the importance of zoonotic bacteria such as atypical EPEC, Campylobacter, STEC, and Salmonella as pathogens associated with acute diarrhea in these children. The findings also reinforce our previous communications about the regional importance of non-O157 STEC strains in severe infant food-borne diseases.

Hemolytic uremic syndrome with mild renal involvement due to Shiga toxin-producing Escherichia coli (STEC) O145 strain.

Hemolytic uremic syndrome (HUS) is a disorder characterized by the presence of the classic triad: microangiopathic hemolytic anemia, thrombocytopenia and acute renal injury. HUS without acute renal failure can be confused with other hematologic diseases. An infantile HUS caused by a Shiga-toxin-producing Escherichia coli (STEC) O145 strain carrying genotype stx2, ehxA, eae subtype ß1 is herein reported. The infant did not require dialysis during the acute stage of HUS, evolved favorably, maintained normal blood pressure and normal renal function and had no recurrence until the last control. This could be due to several factors, such as the characteristics of infecting STEC strain and a reduction in host susceptibility to renal injury. This report highlights the regional participation of non-O157 STEC in childhood diseases and the importance of performing active surveillance for all forms of HUS.

Síndrome urémico hemolítico con compromiso renal leve debido a una cepa de Escherichia coli productora de toxina Shiga [Shiga-toxin-producing Escherichia coli (STEC)] 0145 / Hemolytic uremic syndrome with mild renal involvement due to Shiga toxin-producing Escherichia coli (STEC) 0145 strain

El síndrome urémico hemolítico (SUH) es una afección caracterizada por la presencia de la tríada clásica: anemia hemolítica microangiopática, trombocitopenia y compromiso renal agudo. Los casos de SUH sin insuficiencia renal pueden confundirse con otras enfermedades hematológicas. Presentamos un caso de SUH pediátrico causado por una cepa de Escherichia coli productora de toxina Shiga Shiga-toxin-producing Escherichia coli (STEC) O145 con el genotipo stx2, ehxA, eae subtipo ?1. El niño no requirió diálisis durante la etapa aguda del SUH, evolucionó favorablemente y no tuvo recurrencias hasta el último control; además, mantuvo cifras normales de presión arterial y función renal normal. Esto puede deberse a varios factores: características de la cepa STEC infectante y susceptibilidad del hospedero al daño renal, entre otros. Este hallazgo destaca la participación regional de STEC no-O157 en enfermedades de la infancia y la importancia de realizar una vigilancia activa de todas las formas de SUH

Hemolytic uremic syndrome (HUS) is a disorder characterized by the presence of the classic triad: microangiopathic hemolytic anemia, thrombocytopenia and acute renal injury. HUS without acute renal failure can be confused with other hematologic diseases. An infantile HUS caused by a Shiga-toxin-producing Escherichia coli (STEC) O145 strain carrying genotype stx2, ehxA, eae subtype ?1 is herein reported. The infant did not require dialysis during the acute stage of HUS, evolved favorably, maintained normal blood pressure and normal renal function and had no recurrence until the last control. This could be due to several factors, such as the characteristics of infecting STEC strain and a reduction in host susceptibility to renal injury. This report highlights the regional participation of non-O157 STEC in childhood diseases and the importance of performing active surveillance for all forms of HUS

Valoración de un procedimiento de inmunofluorescencia indirecta para la detección de anticuerpos tipo IgM (IF-IgM) utilizado en el diagnóstico temprano de leptospirosis / Evaluation of an indirect immunofluorescence assay for detection of IgM (IF-IgM) type antibodies in the early diagnosis of leptospirosis

Introducción: la leptospirosis es una enfermedad febril, aguda, que presenta manifestaciones clínicas variadas. Esto dificulta o retarda el diagnóstico clínico, por lo cual es útil disponer de métodos de laboratorio adecuados para orientar el manejo inicial de estos pacientes. Objetivo: evaluar un procedimiento de inmunofluorescencia para detectar IgM (IF-IgM) de elaboración propia aplicado al diagnóstico temprano de leptospirosis. Material y método: se analizaron por IF-IgM y microaglutinación (MAT) (tomada como estándar de referencia) sueros obtenidos de pacientes con sospecha clínica de leptospirosis. La sensibilidad y especificidad de la IF-IgM versus MAT se establecieron utilizando una tabla de doble entrada. La concordancia entre dos observadores se determinó por el test Kappa. Resultados: de 161 muestras precoces analizadas, 97 sueros correspondieron a pacientes con infección aguda confirmada por MAT y 64 sin infección. La sensibilidad y especificidad de la IF-IgM con sueros de fase aguda fueron 79% y 100%, respectivamente. El índice Kappa fue 1. Conclusiones: la IF-IgM aparece como una herramienta útil para el diagnóstico temprano de pacientes con leptospirosis. No requiere el manejo de bacterias viables, puede realizarse en laboratorios que cuenten con microscopio de luz ultravioleta, se necesita una sola muestra de suero y el resultado está listo en tres a cuatro horas. En cuanto a las desventajas, no identifica los serovares involucrados y un resultado negativo no descarta la infección. Teniendo en cuenta esto último es obligatorio analizar por MAT una segunda muestra de suero obtenida a los 10-20 días de la primera para descartarla o confirmarla...

Hemolytic uremic syndrome with mild renal involvement due to Shiga toxin-producing Escherichia coli (STEC) O145 strain. / Hemolytic uremic syndrome with mild renal involvement due to Shiga toxin-producing Escherichia coli (STEC) O145 strain.

Hemolytic uremic syndrome (HUS) is a disorder characterized by the presence of the classic triad: microangiopathic hemolytic anemia, thrombocytopenia and acute renal injury. HUS without acute renal failure can be confused with other hematologic diseases. An infantile HUS caused by a Shiga-toxin-producing Escherichia coli (STEC) O145 strain carrying genotype stx2, ehxA, eae subtype ß1 is herein reported. The infant did not require dialysis during the acute stage of HUS, evolved favorably, maintained normal blood pressure and normal renal function and had no recurrence until the last control. This could be due to several factors, such as the characteristics of infecting STEC strain and a reduction in host susceptibility to renal injury. This report highlights the regional participation of non-O157 STEC in childhood diseases and the importance of performing active surveillance for all forms of HUS.

Usefulness of real-time PCR assay targeting lipL32 gene for diagnosis of human leptospirosis in Uruguay.

INTRODUCTION: Assays based on DNA amplification can provide information that contributes to the initial management of patients with leptospirosis. However, these have not been adopted in Uruguay. Our aim was to evaluate the performance of the lipL32 real-time PCR (qPCR) for diagnosis of leptospirosis. METHODOLOGY: We analyzed by microscopic agglutination test (MAT) and lipL32 qPCR serum samples from 183 patients with suspected leptospirosis. To establish the analytical sensitivity of the qPCR, experimentally spiked samples with known amounts of Leptospira interrogans were analyzed. RESULTS: The analytical sensitivity of the qPCR was 102 leptospires/mL. In 98 patients MAT results were negative meanwhile 85 showed positive reactions, revealing acute infections. Twenty six acute-phase sera of these 85 patients showed a positive signal by qPCR (diagnostic sensitivity 30%). In these patients the average time between onset of symptoms and collection of the first sample was 8 days. In patients with negative results for qPCR and positive MAT results (n=59) the average interval between onset of symptoms and collection of the first sample was 13 days. The qPCR did not yield false positive results. CONCLUSIONS: The qPCR had a lower diagnostic sensitivity than MAT and a higher cost. However, it allowed to make an early diagnosis in 26 patients. In patients with confirmed acute infections and negative results by qPCR, more than 8 days had elapsed between the onset of the illness and extraction of the first serum sample. Our data support that the qPCR from sera have clinical utility within the first week of illness.

Two cases of urinary tract infection caused by Shiga toxin-producing Escherichia coli O157:H7 strains.

STEC strains can infect extra-intestinal sites such as the human urinary tract and sometimes cause severe complications. We report two cases of urinary tract infection caused by STEC in two elderly women with comorbidities. Although both strains belonged to the O157:H7 serotype and carried genes associated with severe illness, none of the patients developed hemolytic uremic syndrome (HUS). These findings provide additional evidence for the presence of these agents in our country and in the region, and highlight the need to maintain an active surveillance system of HUS cases, placing special emphasis on the study of other sites of infection in patients with non-diarrheal HUS.

A ten-year follow-up of human leptospirosis in Uruguay: an unresolved health problem.

Leptospira spp. are delicate bacteria that cannot be studied by usual microbiological methods. They cause leptospirosis, a zoonotic disease transmitted to humans through infected urine of wild or domestic animals. We studied the incidence of this disease in the Uruguayan population, its epidemiologic and clinical features, and compared diagnostic techniques. After examining 6,778 suspect cases, we estimated that about 15 infections/100,000 inhabitants occurred yearly, affecting mainly young male rural workers. Awareness about leptospirosis has grown among health professionals, and its lethality has consequently decreased. Bovine infections were probably the principal source of human disease. Rainfall volumes and floods were major factors of varying incidence. Most patients had fever, asthenia, myalgias or cephalalgia, with at least one additional abnormal clinical feature. 30-40% of confirmed cases presented abdominal signs and symptoms, conjunctival suffusion and altered renal or urinary function. Jaundice was more frequent in patients aged > 40 years. Clinical infections followed an acute pattern and their usual outcome was complete recovery. Laboratory diagnosis was based on indirect micro-agglutination standard technique (MAT). Second serum samples were difficult to obtain, often impairing completion of diagnosis. Immunofluorescence was useful as a screening test and for early detection of probable infections.

A ten-year follow-up of human leptospirosis in Uruguay: an unresolved health problem / Diez años de seguimiento de la leptospirosis humana en Uruguay: un problema de salud no resuelto

Leptospira spp. are delicate bacteria that cannot be studied by usual microbiological methods. They cause leptospirosis, a zoonotic disease transmitted to humans through infected urine of wild or domestic animals. We studied the incidence of this disease in the Uruguayan population, its epidemiologic and clinical features, and compared diagnostic techniques. After examining 6,778 suspect cases, we estimated that about 15 infections/100,000 inhabitants occurred yearly, affecting mainly young male rural workers. Awareness about leptospirosis has grown among health professionals, and its lethality has consequently decreased. Bovine infections were probably the principal source of human disease. Rainfall volumes and floods were major factors of varying incidence. Most patients had fever, asthenia, myalgias or cephalalgia, with at least one additional abnormal clinical feature. 30-40% of confirmed cases presented abdominal signs and symptoms, conjunctival suffusion and altered renal or urinary function. Jaundice was more frequent in patients aged > 40 years. Clinical infections followed an acute pattern and their usual outcome was complete recovery. Laboratory diagnosis was based on indirect micro-agglutination standard technique (MAT). Second serum samples were difficult to obtain, often impairing completion of diagnosis. Immunofluorescence was useful as a screening test and for early detection of probable infections.

El género Leptospira comprende bacterias delicadas, que requieren métodos de estudio especiales. Causan una zoonosis transmitida a los seres humanos por la orina de animales domésticos o silvestres. Estudiamos la incidencia de la leptospirosis en la población humana de Uruguay, sus características epidemiológicas y clínicas, y comparamos técnicas diagnósticas. Tras examinar 6778 casos sospechosos, estimamos que anualmente ocurren unas 15 infecciones/100.000 habitantes, principalmente en trabajadores rurales jóvenes de sexo masculino. El nivel de alerta sobre la leptospirosis ha avanzado en el personal sanitario, y su letalidad ha descendido. La enfermedad humana se asocia principalmente con las infecciones bovinas. Lluvias e inundaciones influyen sobre su incidencia. La mayoría de los pacientes experimentaron fiebre, astenia, mialgias o cefaleas, con al menos un síntoma o signo adicional. 30 a 40% presentaban sintomatología abdominal, hiperemia conjuntival o alteraciones nefro-urológicas. La ictericia era más frecuente en mayores de 40 años. La enfermedad era habitualmente aguda y la recuperación completa. El diagnóstico de laboratorio se basó en la técnica de microaglutinación (MAT), con cepas vivas de distintos serovares. Se requieren segundas muestras de suero, de difícil obtención. El test de inmunofluorescencia se reveló útil para screening y detección precoz de la infección.

Genomic Comparison of the Closely Related Salmonella enterica Serovars Enteritidis and Dublin.

The Enteritidis and Dublin serovars of Salmonella enterica are closely related, yet they differ significantly in pathogenicity and epidemiology. S. Enteritidis is a broad host range serovar that commonly causes gastroenteritis and infrequently causes invasive disease in humans. S. Dublin mainly colonizes cattle but upon infecting humans often results in invasive disease.To gain a broader view of the extent of these differences we conducted microarray-based comparative genomics between several field isolates from each serovar. Genome degradation has been correlated with host adaptation in Salmonella, thus we also compared at whole genome scale the available genomic sequences of them to evaluate pseudogene composition within each serovar.Microarray analysis revealed 3771 CDS shared by both serovars while 33 were only present in Enteritidis and 87 were exclusive to Dublin. Pseudogene evaluation showed 177 inactive CDS in S. Dublin which correspond to active genes in S. Enteritidis, nine of which are also inactive in the host adapted S. Gallinarum and S. Choleraesuis serovars. Sequencing of these 9 CDS in several S. Dublin clinical isolates revealed that they are pseudogenes in all of them, indicating that this feature is not peculiar to the sequenced strain. Among these CDS, shdA (Peyer´s patch colonization factor) and mglA (galactoside transport ATP binding protein), appear also to be inactive in the human adapted S. Typhi and S. Paratyphi A, suggesting that functionality of these genes may be relevant for the capacity of certain Salmonella serovars to infect a broad range of hosts.

Characteristics of Community-Associated Methicillin-Resistant Staphylococcus aureus (CA-MRSA) Strains Isolated from Skin and Soft-Tissue Infections in Uruguay.

We analyzed 90 nonduplicates community-associated methicillin-resistant S. aureus (CA-MRSA) strains isolated from skin and soft-tissue infections. All strains were mecA positive. Twenty-four of the 90 strains showed inducible macrolide-lincosamide-streptogramin B resistance. All strains produced alpha-toxin; 96% and 100% of them displayed positive results for lukS-F and cna genes, respectively. Eigthy-five strains expressed capsular polysaccharide serotype 8. Six different pulsotypes were discriminated by pulsed-field gel electrophoresis (PFGE) and three predominant groups of CA-MRSA strains (1, 2, and 4) were identified, in agreement with phenotypic and genotypic characteristics. Strains of group 1 (pulsotype A, CP8+, and Panton-Valentine leukocidin (PVL)+) were the most frequently recovered and exhibited a PFGE band pattern identical to other CA-MRSA strains previously isolated in Uruguay and Brazil. Three years after the first local CA-MRSA report, these strains are still producing skin and soft-tissue infections demonstrating the stability over time of this community-associated emerging pathogen.